Brake mechanism



. 1,694,203 F. BRAULT ET flu.V

BRAKE MECHANI SM Dec. 4, 1928.

Filed 0Gt l2, 1927 2 Sheets-Sheet l 1,694 203 Dec' 4' '1928' F 'BRAULT ET AL BRAKE MECHANISM Filed Oct. 12, 1927 2 Sheets-Sheet 2 BHUBBDUUUDUBDHHUUUU' Patented Dec. 4, 1928. l

UNITED 'STATES V1,694,203 PATENT oFFlcE.

BRAKE MECHANISM.

Application sled october 12, 1927, serial No. 225,773, 'and This invention relates-to improvements in brakes of a known type comprlsing a metallic band coiled into circular form and which of these rods in opposite directions are caused by the manipulation of the ke or controlling device E. Rigid members suc pieces F-F1 and G-G1, attached. by one arm F1, G1 to the band, guide this latter,'at its middle part by means of the other arms F. G on each side of a fixed supportl I-I.' The clamping or braking action is'obtained by a rotation of the key in the direction of the arrow, Fig. 1, the rods or links C, D causing forces to be produced which separatev the ex tremities A1, A2 of the band, forcin them apart as shewn at Fig. 2.y This bang bein rigidly guided at its middle portion, is force by this latter against the drum B. But when the drum turns, for instance in the opposite direction to the hands of a watch, .that

is to say in the opposite direction to the manipulating key, only the right hand portion of the band comprised between the fixed support H and the extremity Al tends to rest pressed against the drum, as shewn by the arrow at 1 in Fig. 2, the portion on the left H-A1. tending, on the contrary, to become loose, as shewn by the arrow at 2 in Fig. 2. The result is that there is'a clamping or braking action which is not. progressive and which is incomplete, only one o? the halves of the hand producing an effective braking, in whichever. direction the drum may be rotating. i The improvements, formin the object o f the present invention, entire y obviate this drawback and allow for a braking action which is altogether rogressive andcomplete to be exerted by the and upon the drum.

According to the invention, the band is guided in a rigid radial guide formed in the fixed portion, the guiding being effected byv means of suitable exi'ble fingers constituted,

as right angle in France October 13, 1926.

for example, by angled or like piece, of which the other arm is attached to the band. This is the constructional embodiment of the invention which is represented by way of example in the accompanymg drawings.

In these drawings, as previously stated, Figs. 1 and 2 are diagrams illustrating known constructions.

Fig. 3 shews the improved braking device, constructed according to the invention, in side elevation in the inoperative position.

Figs. 4 and 5 are part sections respectively on 4.-4 and 5"-5 o Fig. 3. f Fig. v6 is a part sectional elevation correone of the arms of a right sponding to Fig. 3, shewing the parts in the operative position for braking.

Figs. 7 and 8 and 9 are diagrams illustrat-` ing the operation of the apparatus.

In these figures, A denotes'the band, of steel, covered for instance by a band of ferrodo a., and of which the extremities A1, A', are pivotally connected to links C, D of adjustable lengt-h,the pressure or push bein produced 'in a known manner, "by means o buttons e of a key E. B denotes the drum l rigidly connected as awheel of a vehicle for example.

According to the invention, the band is guided. at its middle portion, by means of radial flexible fingers F, G, constituted for instance by the free arms of two rightangle pieces, the other arms of whiehFl, G1 are xed to the band. The guiding is ensured by the arrangement of these fingers in a radial guide, constituted for example by ga. clip. In the example shewn, the branches of the clip are formed by rejecting arms Il projecting from the fixe portion I and the ase of theclip is formed by a cap J ixed to thebranches by means of screws y.

The-flexible fingers F, G between which a suitable space is left, rest on small steel lplates to the rotary element, such other extremityof which is attached to a -button I2 projecting from the fixed disc I (or If the key E is manoeuvred or turnedthe extremities A1 and A2 of the band which, in the out of use position, are in the position shewn in Figs. 3 land 7, are moved away from one another, and the opening out of the band tends immediately to produce a clamping or 1 a ainst the plates and the method of guiding braking action of the flexible fingers F, G K. However, the flexibllity of the fingers and the space for play provided between them allows them to become slightly out of shape, by restin on the plates and this allows in general for t e band after it has come to rest on the drum (Fig. 8) to move with this latter for a short time during its movement of rotation; as shewn in Figs; 6 and'9. The braking points of the band on the drum which were originally at 1, 1, Fig. 6, move to 2, 2. Lastly, the band in place of being separated from the drum, by the portion to the left thereof, maintains contact on the contrary, and progressively, with the wall, and this adherence is a direct function of the velocity of rotation of the drum.

The employment of flexible radial fingers them on the interior of the guide against the walls of the parts from which they might receive support at the same time that one is supported by the other, by reason of the small separation or space left between them, permits, as will be seen from the beginnino' of the clamping an angular movement of t e band in the direction of rotation of the drum. This movement permits of the compensation for the slight variations of length of the rods C and D, and 4't ensures above all, as has been seen, the adhesion of the band as a whole with the inner wall of the drum, whatever may be the direction of motion or rotation'of the drum.

The radial guidin of one of the fingers in the immediate neig bourhood of the other finger allows, on the one hand, for ensuring the return by a radial spring attached to one of the two fingers.

What we claim and desire to secure by Letters Patent of the United States of America is 1. A band brake forthe wheels of vehicles and for other purposes comprising a metallic band the extremities of which are ivoted to rods of adjustable length controlle Y in order to se arate the extremities, by a key; characterized by the" fact that the guiding of the middle portions of the band with res ect to a fixed portion is effected by means of exible radial fingers in rigid connection with the band andxkept at a slight distance apart on the interior of a radial fixed guide so that on the radial displacement of the fingers due to the separation of the extremities of the band, their transverse flexion may follow by contact with the walls of the guide and mutual contact between the fingers under the effect of the movement of the band by the drum.

2. A'constructional form of mechanism as claimed in claim 1 'in which the flexible fingers are constituted each by one of the arms of a right angled member of which the other arm is attached to the band, the guide being formed by a clip the arms of which are provided with steel plates which serve for supports for the fingers and which are covered in by a cap, the free extremity of one of the fingers serving for attachment of one of the extremities of a radial return spring connected by its other extremity to a fixed button.

3. In brake mechanism of the type described, a construction including a hollow drum, a circular split band, means for separating the ends of the band, a flexible proJection at the middle of the band and fixed means co-operating with the flexible rojection to restrain its movement in either direction substantially as and for the purposes set forth.

In witness whereof we aflix our signatures.

FRANois BRAULT. ANDR CORDIER. 

